Feeling-bolt-hole gauge



Feb. 14,1928. 1,658,994

K. LAUER FEELING BOLT HOLE GAUGE Filed Feb.l3, 1925 2 Sheets-Sheet 1Fig. 1.

Feb. 14, 1928. 4 1,658,994

' K. LAUER FEEIIINQ BOLT HOLE GAUGE Filed Feb.13 19,25 2.8heets-Sheot 2'Illllulllllll W: Hui BM WWW Patented Feb. 14, 1928.

KARL LAUER, OF ESSFN, GERMANY, ASSIGNOR TO FRIED. KRUPP AKTIENGESELL- SCI-I AFT, OF ES SEN-ON-THE-RUHR, GERMANY.

rEnLrNG-BoL'r-Hom GAUGE.

Application filed February 13,1925, Serial No. 9,038, and in GermanyMareh 1, 1924.

- Feeling bolt hole gauges are already wellknown in which all gaugingand supporting bolts act on an inclined plane of a member movableangularly to their" direction of movement. These gauges have thedrawback thatin testing obliquely or horizontally arranged bores theweight of the gauge disadvantageously influences the accuracy of themeasuring. Besides, feeling bolt hole gauges are already known in whichone of the gauging bolts is rigidly connected with the gauge casing andthe supporting bolts'are spring-pressed so as to be movable outwardsindependently from one another and from the gauging bolts. lVith thesegauges a perfect measuring is likewise impossible as, owing to theyieldingness of the supporting bolts, it may easily occur that a chordinstead of the diameter of the bore to be tested is measured. 1

The invention has for its object to avoid the said drawbacks and toprovide a feeling bolt hole gauge which permits of the: most accuratemeasuringv not only of vertical bores but also of obliquely orhorizontally disposed bores}v The invention will now be described withreference to the accompanying drawing which illustrates, asan embodimentof the subject-matter of the invention, a spreadable feeling bolt holegauge, and in which:

Fig. 1 is asection through the gauge, 7 Fig. 2 the corresponding planview, partly in section, and

Fig. 3 an elevation of the gauge, partly in section, along the line 33of Fig. 2.

A casing A, Fig. 1, having a cylindrical upper portion is provided atits lower end i with four arms A A A and A U-shaped 40 in cross sectionopen at their lower side and having mounted in their hollow spaces twogauging bolts B and B and two supporting bolts 13 and B The casing andthe arms are closed at the lower side by a cover C. The distance betweenthe end faces of the gauging-bolts B and B is preferably a lit-v tlelarger than the distance between the end faces of-the supporting bolts Band B The upper surface 6 of the gauging bolt B curved edge' in contactwith .thelower surface; of the top of the arm A and adjustably held inthis position by meansoi screws 6? and 6 The end of the gauging bolt Blying is curved; The gauging bolt B is by itstowards the centrallongitudinal axis of the gauge casing is provided with a U-shaped groove3) which is inclined with relation to thesaid axis and open at its upperside. A rotary member D having the shape of a zone of a sphere isadapted to. roll in the groove 6 see Figs. 1 and 3. The inner end faceof the shiftable gauging bolt B bears against the circumference of therotary member D under the action of a pressure spring E, Fig. 1. The twosupporting bolts B and B are shiftable in the arms A and A in a mannersimilar to the gauging bolt B They are placed under the action of twopressure springs E and EflFig. 3, by which the ends lying towards thecentral axis of thegauge are held in contact with twowedges F and Fwhich are movable vertically with relation" to the direction ofmoiiement of the bolts B B wedges are rigidly connected by means of ascrew f with a transfer bolt F which. is mounted for longitudinalshifting motion in the casing A and-provided at its lower end with aprismatic head 7 extendingbetween the wedges F and F andbeing in contactwith the rotary,member D,,Figs. 1 and 3. On a cylindrical portion fotthe'bolt F is shiftably mounted a sleeve G whichhas an annular collar9 The-shiftingmovement of thesl eeve G is limitedby a contracted portiona of the casing A,v The portion f carries'a cross pin 7 which engages anoblong hole 9 of the sleeve G and permits the bolt F to make a slightlongitudinal shifting movement with relation to the sleeve G. A] springH interposed between a shoulder of the bolt F and the collar 9 of thesleeve G holds the cross pin f' in contact with the lower end face 01":the oblong hole when the gauge is in its position of rest. The spring His so strong that itis able to overcomethe pressure of the three springsE, E and E which act against it. A sleeve J, Fig. 1, slotted at itsupper and lower end and surroundingthecasing A is shittable on thecasing A and adapted to be clamped to the latterby means of ascrew 71The upper end ofthe sleeve J which is provided with a clamping screw'11, surrounds a precision indicatonK of a known type the housing Kofrwhich is in contact with the sleeve while itslfeelin g bolt k is incontact with the bolt F. The

The said bolt ot the precision indicator K outer screw-threaded ends ofthe gauging and feeling bolts have removably liXGQl to them by means olcap nuts L apin L each (see particularly i).

\fhen introducing the gauge into the bore to be tested, the movablegauging bolt 15, which bears against the. rotary member 1) under theaction of the spring 15 (Fig. 1),

'is pushed imvardly. At the same time, the

member D rolling along the inclined base of the groove Z), exerts apressure on the head 7" of the bolt F and shifts the same upwardlycontrary to the action of the spring H. The inclination of the groove Z)is adjustable by means of the two screws 6* and I) so that the ratio oftransmission between the shiftable gauging bolt B and the feeling may beaccurately regulated. The leeilng bolt 70 which is in contact with thebolt l! is likewise shifted upwardly by the latter, whereby theindicating device of the precision indicator K is caused to indicate ina manner known the measure of the shifting movement of the gauging bolt1%. The shifting movement of the bolt F is limited by the oblong hole 9the dimensions of which are chosen in accordance with the measuringrange of the precision indicator K. During the shifting movement of thetransfer bolt F the wedges F and F rigidly connected to it likewisechange their position; they move upwardly too and the supporting boltsand B Fig. 3, which are in contact with the wedges, follow the saidmovement under the action of the springs E and E The inclination of thewedges F and F and of the groove b. may be chosen so that a pressureexerted on the end faces of the supporting bolts B or B cannot produceashifting movement of the bolt F and therefore cannot actuate theindicating device, and that each supporting bolt is shifted by half theway made by the gauging bolt B Therefore the outer distance between theend. faces of the two gauging bolts always remains a little larger thanthe corresponding distance between the end faces of the two supportingbolts. If it is desired to change the measuring range of the gauge, thetwo clamping screws 2' and '1' are loosened and the gauge is introducedinto a standard caliper ring of the COl'lt-BSPODCl'lIlg size, whereuponthe precision indicator K and the sleeve J are shifted with relation toeach other and to the casing A of the gauge until the indicating deviceregisters with the zero mark. If the two clamp iug screws 2' and i arethen retightened, the gauge is again ready for use. In connectiontherewith a millimeter scale a on the outer side of the casing A is usedfor coarsely adjusting the sleeve J with relation to the cas ing A.while for the accurate adjustment the precision indicator K ispreferably shifted in its holder. In order to increase the meas;

uring range even more, the nuts L may be removed and the pins L replacedby other pins of greater length.

The subject-matter of the invention possesscs over the well-knownfeeling bolt hole gauges the advantage of allowingan accurate measuringalso of obliquely or horizontally arranged bores, because the gauge thenrests on the non-shiftable gauging bolt so that its weight does not haveany influence on the measuring.

I claim- 1. A hole gauge comprising in combination a casing, a movableand a stationary gauging bolt mounted in said casing, at least twosupporting bolts shiftably mounted in said casing, an indicating device,a bolt for transferring the movement of the movable gauging bolt to theindicating device, and soiftable parts provided with planes in-- clinedto the axes of the supporting bolts. these shiftable parts being rigidlyconnected with the said transferring bolt and arranged for cooperationwith the supporting bolts so as to cause the latter to be dependent intheir movements on the said shiftable parts, a rotary member interposedbetween the movable gauging bolt and the said transfer bolt and arrangedbetween the said shiftable parts, and a part rigidly connected with saidcasing and having a plane inclined to the direction of movement of saidmovable gauging bolt and designed to support the rotary member forrolling motion on it.

2. A hole gauge comprising in combination a casin a movable andastationary gaugiug bolt mounted in said casing, at least two supportingbolts shiftably mounted in said casing, an indicating device, abolt fortransferring the movement of the movable gauging bolt to the indicatingdevice, and shiftable part provided with planes inclined to the axes ofthe supporting bolts, these shiftable parts being rigidly connected withthe said transferring bolt and arranged for cooperation with thesupporting bolts so as to cause the latter to be dependent in theirmovements on the said shiftable parts, a rotary member interposedbetween the mov able gauging bolt and the said transfer bolt andarranged between the said shiftable parts, a part rigidly connected withsaid ca sing and having a plane inclined to the direction of movement ofsaid movable ganging bolt and designed to support the rotary member forrolling motion on it, and means for varying the inclination of the lastsaid inc-lined plane.

3. A hole gauge comprising in combination a movable and a stationarygauging bolt, at least two shiftable supporting bolts, an indicatingdevice, a bolt for transferring the movement of the movable gauging boltto the indicating device and shiftable parts provided with planesinclined to the axes inclination of the inclined planes oi the shiftableparts being of such a kind that a pressure exerted only on the end facesof the supporting bolts cannot produce a shifting movement of the saidtransfer bolt.

4. A hole gauge comprising in. combination a casing, amovable and astationary gauging bolt mounted in said casing, at least two supportingbolts shiftably mounted in said casing, an indicating device a bolt fortransferring the movement of the movable gauging boltto the indicatingdevice, and shi'l table parts provided with planes inclined to the axesof the supporting bolts, these shiftable parts being rigidly connectedwith the said transferring bolt and arranged for cooperation with thesupporting bolts so as to cause the latter to be dependent in theirmovement on the said 'shiftable parts, a rotary member interposedbetween the movable gauging bolt and the said transferring bolt andarranged between the said shiftable parts, and a part rigidly connectedwith said casing and having a plane inclined to the direction ofmovement of said movable gauging bolt and designed to support the rotarymember for rolling motion on it, the inclinations of the inclined planesof the shiftable parts cooperating with the supporting bolts and of theinclined plane rigidly connected with the casing'being chosen sothat theshifting movement of each supporting bolt is about equal to half thelength of the corresponding shifting movement of the gauging bolt.

5. A hole gauge comprising a casing, a plurality 01'' supporting boltsslidably mounted in said casing, a gauging bolt stationarily mounted insaid casing, -a second gauging bolt slidably mounted in said casing, andtransmission means between said movable gauging bolt and saidsupportingbolts whereby the latter are shifted by the former.

The foregoing specification signed at Essen, Germany, this 14th day ofJanuary,

K-ARL LAUER.

